Published 12:00 am Tuesday, March 8, 2011

by Gail Poulton

North Carolina is one of the top 10 states in roundabout construction. There are 85 roundabouts on state-maintained roads, according to James Dunlop, NCDOT congestion management engineer. Some 200-300 roundabouts have been built on smaller roads in the state.  

Some 20,000 roundabouts have been constructed in the United Kingdom and 15,000 in France, compared about 2,000 in the U.S. Why the disparity? Replacing traffic-light controlled intersections with roundabouts often meets resistance, Dunlop says.

One main reason Americans are reluctant to embrace roundabouts is that they may equate roundabouts with the traffic circles built during the 1950s.  

“The problem with these traffic circles is they were too big and cars traveled at too high of speeds,” says Dunlop. That made them both unsafe and intimidating to drivers because drivers needed a large gap between circling cars to enter. As a result, the traffic circles quickly fell out of favor.

In fact, many states are either removing these traffic circles or replacing them with roundabouts, Dunlop says.

Modern roundabouts, which began being constructed in England and Australia in the 1960s, are much smaller so “that brings down speed and makes them more efficient and much safer,” explains Dunlop. As a result of their success, roundabouts have spread throughout Europe and are gaining popularity in the U.S., where the first one was built in Las Vegas in the early 1990s.

“The huge benefit from a traffic standpoint is that during off-peak hours you keep going versus a signal where you have to stop and idle for at least 10 seconds,” says Dunlop. The benefit from an air quality standpoint? Cleaner, healthier air.